Method for controlling laser power in a texturing process
US5790433A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 1996 |
| Grant date | Aug 4, 1998 |
| Priority date | — |
| Expiry date | Sep 5, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/84
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disk texturing tool is used, for example, to provide textured spots in an annular portion of both sides of a disk for a hard disk drive. Disks are moved into and out of the texturing process in cassettes, through two disk-handling stations. An optical system includes a laser directed at a beamsplitter to split the laser beam into two beams having approximately power, which are directed along parallel paths through a power control optics block to expose simultaneously opposite sides of a disk to be textured. The power level of each of these two beams is controlled by a program which operates in a teach mode to develop a look up table describing laser beam power as a function of a signal driving an attenuator, in a set point mode setting this drive signal to provide a certain laser beam power, in a run mode controlling this power through a feedback loop, and in a display mode showing laser beam power as a function of time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.